<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>demo04</title>
  <script src="../lib/react.js"></script>
  <script src="../lib/react-dom.js"></script>
  <script src="../lib/browser.js"></script>
</head>
<body>
<div id="root"></div> 
<!-- 
React component 可以是一个函数，返回一个 React element

 -->
<script type="text/babel">
function Welcome(){
  return <h1> Welcome, John </h1>;
}
var element = <Welcome />;
console.log(element);
console.log( Welcome() );

ReactDOM.render(
  <Welcome />,
  document.getElementById('root')
);
</script>
</body>
</html>